| Message ID | 20210422081508.3942748-17-tientzu@chromium.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | Restricted DMA | expand |
On Thu, Apr 22, 2021 at 4:17 PM Claire Chang <tientzu@chromium.org> wrote: > > If a device is not behind an IOMMU, we look up the device node and set > up the restricted DMA when the restricted-dma-pool is presented. > > Signed-off-by: Claire Chang <tientzu@chromium.org> > --- > drivers/of/address.c | 25 +++++++++++++++++++++++++ > drivers/of/device.c | 3 +++ > drivers/of/of_private.h | 5 +++++ > 3 files changed, 33 insertions(+) > > diff --git a/drivers/of/address.c b/drivers/of/address.c > index 54f221dde267..fff3adfe4986 100644 > --- a/drivers/of/address.c > +++ b/drivers/of/address.c > @@ -8,6 +8,7 @@ > #include <linux/logic_pio.h> > #include <linux/module.h> > #include <linux/of_address.h> > +#include <linux/of_reserved_mem.h> > #include <linux/pci.h> > #include <linux/pci_regs.h> > #include <linux/sizes.h> > @@ -1109,6 +1110,30 @@ bool of_dma_is_coherent(struct device_node *np) > } > EXPORT_SYMBOL_GPL(of_dma_is_coherent); > > +int of_dma_set_restricted_buffer(struct device *dev) > +{ > + struct device_node *node; > + int count, i; > + > + if (!dev->of_node) > + return 0; > + > + count = of_property_count_elems_of_size(dev->of_node, "memory-region", > + sizeof(phandle)); > + for (i = 0; i < count; i++) { > + node = of_parse_phandle(dev->of_node, "memory-region", i); > + /* There might be multiple memory regions, but only one > + * restriced-dma-pool region is allowed. > + */ > + if (of_device_is_compatible(node, "restricted-dma-pool") && > + of_device_is_available(node)) > + return of_reserved_mem_device_init_by_idx( > + dev, dev->of_node, i); > + } > + > + return 0; > +} > + > /** > * of_mmio_is_nonposted - Check if device uses non-posted MMIO > * @np: device node > diff --git a/drivers/of/device.c b/drivers/of/device.c > index c5a9473a5fb1..d8d865223e51 100644 > --- a/drivers/of/device.c > +++ b/drivers/of/device.c > @@ -165,6 +165,9 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, > > arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); > > + if (!iommu) > + return of_dma_set_restricted_buffer(dev); > + > return 0; > } > EXPORT_SYMBOL_GPL(of_dma_configure_id); > diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h > index d717efbd637d..e9237f5eff48 100644 > --- a/drivers/of/of_private.h > +++ b/drivers/of/of_private.h > @@ -163,12 +163,17 @@ struct bus_dma_region; > #if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA) > int of_dma_get_range(struct device_node *np, > const struct bus_dma_region **map); > +int of_dma_set_restricted_buffer(struct device *dev); > #else > static inline int of_dma_get_range(struct device_node *np, > const struct bus_dma_region **map) > { > return -ENODEV; > } > +static inline int of_dma_get_restricted_buffer(struct device *dev) This one should be of_dma_set_restricted_buffer. Sorry for the typo. > +{ > + return -ENODEV; > +} > #endif > > #endif /* _LINUX_OF_PRIVATE_H */ > -- > 2.31.1.368.gbe11c130af-goog >
On 2021-04-22 09:15, Claire Chang wrote: > If a device is not behind an IOMMU, we look up the device node and set > up the restricted DMA when the restricted-dma-pool is presented. > > Signed-off-by: Claire Chang <tientzu@chromium.org> > --- > drivers/of/address.c | 25 +++++++++++++++++++++++++ > drivers/of/device.c | 3 +++ > drivers/of/of_private.h | 5 +++++ > 3 files changed, 33 insertions(+) > > diff --git a/drivers/of/address.c b/drivers/of/address.c > index 54f221dde267..fff3adfe4986 100644 > --- a/drivers/of/address.c > +++ b/drivers/of/address.c > @@ -8,6 +8,7 @@ > #include <linux/logic_pio.h> > #include <linux/module.h> > #include <linux/of_address.h> > +#include <linux/of_reserved_mem.h> > #include <linux/pci.h> > #include <linux/pci_regs.h> > #include <linux/sizes.h> > @@ -1109,6 +1110,30 @@ bool of_dma_is_coherent(struct device_node *np) > } > EXPORT_SYMBOL_GPL(of_dma_is_coherent); > > +int of_dma_set_restricted_buffer(struct device *dev) > +{ > + struct device_node *node; > + int count, i; > + > + if (!dev->of_node) > + return 0; > + > + count = of_property_count_elems_of_size(dev->of_node, "memory-region", > + sizeof(phandle)); > + for (i = 0; i < count; i++) { > + node = of_parse_phandle(dev->of_node, "memory-region", i); > + /* There might be multiple memory regions, but only one > + * restriced-dma-pool region is allowed. > + */ What's the use-case for having multiple regions if the restricted pool is by definition the only one accessible? Robin. > + if (of_device_is_compatible(node, "restricted-dma-pool") && > + of_device_is_available(node)) > + return of_reserved_mem_device_init_by_idx( > + dev, dev->of_node, i); > + } > + > + return 0; > +} > + > /** > * of_mmio_is_nonposted - Check if device uses non-posted MMIO > * @np: device node > diff --git a/drivers/of/device.c b/drivers/of/device.c > index c5a9473a5fb1..d8d865223e51 100644 > --- a/drivers/of/device.c > +++ b/drivers/of/device.c > @@ -165,6 +165,9 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, > > arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); > > + if (!iommu) > + return of_dma_set_restricted_buffer(dev); > + > return 0; > } > EXPORT_SYMBOL_GPL(of_dma_configure_id); > diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h > index d717efbd637d..e9237f5eff48 100644 > --- a/drivers/of/of_private.h > +++ b/drivers/of/of_private.h > @@ -163,12 +163,17 @@ struct bus_dma_region; > #if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA) > int of_dma_get_range(struct device_node *np, > const struct bus_dma_region **map); > +int of_dma_set_restricted_buffer(struct device *dev); > #else > static inline int of_dma_get_range(struct device_node *np, > const struct bus_dma_region **map) > { > return -ENODEV; > } > +static inline int of_dma_get_restricted_buffer(struct device *dev) > +{ > + return -ENODEV; > +} > #endif > > #endif /* _LINUX_OF_PRIVATE_H */ >
On Fri, Apr 23, 2021 at 9:35 PM Robin Murphy <robin.murphy@arm.com> wrote: > > On 2021-04-22 09:15, Claire Chang wrote: > > If a device is not behind an IOMMU, we look up the device node and set > > up the restricted DMA when the restricted-dma-pool is presented. > > > > Signed-off-by: Claire Chang <tientzu@chromium.org> > > --- > > drivers/of/address.c | 25 +++++++++++++++++++++++++ > > drivers/of/device.c | 3 +++ > > drivers/of/of_private.h | 5 +++++ > > 3 files changed, 33 insertions(+) > > > > diff --git a/drivers/of/address.c b/drivers/of/address.c > > index 54f221dde267..fff3adfe4986 100644 > > --- a/drivers/of/address.c > > +++ b/drivers/of/address.c > > @@ -8,6 +8,7 @@ > > #include <linux/logic_pio.h> > > #include <linux/module.h> > > #include <linux/of_address.h> > > +#include <linux/of_reserved_mem.h> > > #include <linux/pci.h> > > #include <linux/pci_regs.h> > > #include <linux/sizes.h> > > @@ -1109,6 +1110,30 @@ bool of_dma_is_coherent(struct device_node *np) > > } > > EXPORT_SYMBOL_GPL(of_dma_is_coherent); > > > > +int of_dma_set_restricted_buffer(struct device *dev) > > +{ > > + struct device_node *node; > > + int count, i; > > + > > + if (!dev->of_node) > > + return 0; > > + > > + count = of_property_count_elems_of_size(dev->of_node, "memory-region", > > + sizeof(phandle)); > > + for (i = 0; i < count; i++) { > > + node = of_parse_phandle(dev->of_node, "memory-region", i); > > + /* There might be multiple memory regions, but only one > > + * restriced-dma-pool region is allowed. > > + */ > > What's the use-case for having multiple regions if the restricted pool > is by definition the only one accessible? There might be a device coherent pool (shared-dma-pool) and dma_alloc_attrs might allocate memory from that pool [1]. I'm not sure if it makes sense to have another device coherent pool while using restricted DMA pool though. [1] https://elixir.bootlin.com/linux/v5.12/source/kernel/dma/mapping.c#L435 > > Robin. > > > + if (of_device_is_compatible(node, "restricted-dma-pool") && > > + of_device_is_available(node)) > > + return of_reserved_mem_device_init_by_idx( > > + dev, dev->of_node, i); > > + } > > + > > + return 0; > > +} > > + > > /** > > * of_mmio_is_nonposted - Check if device uses non-posted MMIO > > * @np: device node > > diff --git a/drivers/of/device.c b/drivers/of/device.c > > index c5a9473a5fb1..d8d865223e51 100644 > > --- a/drivers/of/device.c > > +++ b/drivers/of/device.c > > @@ -165,6 +165,9 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, > > > > arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); > > > > + if (!iommu) > > + return of_dma_set_restricted_buffer(dev); > > + > > return 0; > > } > > EXPORT_SYMBOL_GPL(of_dma_configure_id); > > diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h > > index d717efbd637d..e9237f5eff48 100644 > > --- a/drivers/of/of_private.h > > +++ b/drivers/of/of_private.h > > @@ -163,12 +163,17 @@ struct bus_dma_region; > > #if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA) > > int of_dma_get_range(struct device_node *np, > > const struct bus_dma_region **map); > > +int of_dma_set_restricted_buffer(struct device *dev); > > #else > > static inline int of_dma_get_range(struct device_node *np, > > const struct bus_dma_region **map) > > { > > return -ENODEV; > > } > > +static inline int of_dma_get_restricted_buffer(struct device *dev) > > +{ > > + return -ENODEV; > > +} > > #endif > > > > #endif /* _LINUX_OF_PRIVATE_H */ > >
diff --git a/drivers/of/address.c b/drivers/of/address.c index 54f221dde267..fff3adfe4986 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -8,6 +8,7 @@ #include <linux/logic_pio.h> #include <linux/module.h> #include <linux/of_address.h> +#include <linux/of_reserved_mem.h> #include <linux/pci.h> #include <linux/pci_regs.h> #include <linux/sizes.h> @@ -1109,6 +1110,30 @@ bool of_dma_is_coherent(struct device_node *np) } EXPORT_SYMBOL_GPL(of_dma_is_coherent); +int of_dma_set_restricted_buffer(struct device *dev) +{ + struct device_node *node; + int count, i; + + if (!dev->of_node) + return 0; + + count = of_property_count_elems_of_size(dev->of_node, "memory-region", + sizeof(phandle)); + for (i = 0; i < count; i++) { + node = of_parse_phandle(dev->of_node, "memory-region", i); + /* There might be multiple memory regions, but only one + * restriced-dma-pool region is allowed. + */ + if (of_device_is_compatible(node, "restricted-dma-pool") && + of_device_is_available(node)) + return of_reserved_mem_device_init_by_idx( + dev, dev->of_node, i); + } + + return 0; +} + /** * of_mmio_is_nonposted - Check if device uses non-posted MMIO * @np: device node diff --git a/drivers/of/device.c b/drivers/of/device.c index c5a9473a5fb1..d8d865223e51 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -165,6 +165,9 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); + if (!iommu) + return of_dma_set_restricted_buffer(dev); + return 0; } EXPORT_SYMBOL_GPL(of_dma_configure_id); diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h index d717efbd637d..e9237f5eff48 100644 --- a/drivers/of/of_private.h +++ b/drivers/of/of_private.h @@ -163,12 +163,17 @@ struct bus_dma_region; #if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA) int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map); +int of_dma_set_restricted_buffer(struct device *dev); #else static inline int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map) { return -ENODEV; } +static inline int of_dma_get_restricted_buffer(struct device *dev) +{ + return -ENODEV; +} #endif #endif /* _LINUX_OF_PRIVATE_H */
If a device is not behind an IOMMU, we look up the device node and set up the restricted DMA when the restricted-dma-pool is presented. Signed-off-by: Claire Chang <tientzu@chromium.org> --- drivers/of/address.c | 25 +++++++++++++++++++++++++ drivers/of/device.c | 3 +++ drivers/of/of_private.h | 5 +++++ 3 files changed, 33 insertions(+)